The present embodiments relate to a radiotherapy system including a therapeutic radiotherapy module and at least one diagnostic X-ray imaging module.
The use of radiation to destroy diseased tissue is a common method in therapeutic medicine. Systems that use high-energy, electromagnetic radiation (e.g., X-rays, gamma radiation), or particle radiation (e.g., electrons, protons, and/or carbon ions) are used for this purpose. The radiation used in radiotherapy may, for example, be in the megavolt (MV) energy range. During the course of a radiotherapy session, the patient is precisely positioned to provide that a body region to be irradiated (e.g., a tumor to be irradiated) is exposed to a sufficiently high radiation dose, but at the same time, the patient's healthy tissue is damaged as little as possible. A localization of a body region of the patient to be irradiated is conventionally performed at regular intervals during the treatment for the purpose of positioning. This may take place with imaging X-ray methods using radiation in the kilovolt (kV) energy range (e.g., using computed tomography). To avoid incorrect positioning of the patient, an examination of this kind may be carried out directly in the irradiation position.
During radiation treatments using radiation from different directions, the beam strikes the tumor for each of the directions. The beams intersect at a point that lies in the region of the tissue to be irradiated. The point may be an isocenter and is an intersection point of the beams corresponding with different irradiation positions.
Published document DE 10 2009 049 074 A1 discloses a radiotherapy system having a therapeutic radiation source and two diagnostic X-ray imaging modules each with an X-ray source and an X-ray detector. FIG. 1 shows a radiotherapy system 1 including a rotatable gantry 2 that is constructed with a cylindrical opening 3, in which a patient 4 undergoing radiotherapy may be at least partially positioned. The patient 4 is positioned by way of a couch 5 in such a way that the tumor of the patient 4 is located in the isocenter of the radiotherapy system 1. A projecting arm 6 is arranged on the gantry 2. A radiation source (not shown in FIG. 1) for a therapeutic treatment beam 7 that strikes the patient 4 during treatment, and a lamella collimator are at least partially located in the projecting arm 6. Also provided on the projecting arm 6 is a holding ring 8 that is concentrically oriented with respect to the isocenter of the radiotherapy system 1. A plane of the holding ring 8 is located in a plane of rotation of the rotatable gantry 2. Two X-ray sources 9 and two X-ray detectors 10 are arranged on the holding ring 8 so as to be movable along the holding ring 8 independently of each other. The position, shown in FIG. 1, of the X-ray imaging module with mutually opposing X-ray sources 9 and X-ray detectors 10 is used to produce an X-ray image or a sequence of X-ray images of the patient 4. When the gantry 2 is rotated, a direction of the therapeutic treatment beam 7, from which the therapeutic treatment beam 7 strikes the patient 4, changes. As the gantry 2 is rotated, the holding ring 8 rotates at the same time. The position of the X-ray sources 9 and the X-ray detectors 10 rotates as well. Since the X-ray sources 9 and the X-ray detectors 10 are arranged on the holding ring 8 so as to be movable independently of each other, the angle may be flexibly adjusted for diagnostic X-ray imaging. The X-ray imaging module and the mobility of the associated X-ray imaging components are tied to the specific embodiment of the projecting arm 6 of the radiotherapy system.